1. Field of the Invention
The invention relates to a stripping means for removing material from between the cutting rollers of shredding machines or the like. In particular, the invention relates to a machine with strippers engaged in a slot between spaced disks of a cutting roller.
2. Prior Art
Such stripping means are described, or example, in DE-OS No. 31 12 666. When moving with the cutting rollers, materials to be stripped encounter the individual strippers simultaneously over the entire roller length. During the conventional forward running of the rollers the materials simultaneously arrive at the primary strippers, located on the undersides of the cutting rollers immediately adjacent to the cutting zone or the roller gap, said primary strippers being arranged over the entire length of the cutting rollers in a straight linear row, and each annular slot between successive disks being occupied by a stripper.
The known stripping means achieves satisfactory results for normal operation, but in certain cases, particularly when the shredding machine undergoes high loading and has a relatively small capacity motor, overloading can occur in sudden bursts. This happens because over the entire length of the machine the cutting rollers are simultaneously decelerated by material arriving at the same time at the primary strippers for each slot.
In the main working rotation direction of the cutting rollers further strippers can be positioned behind the primary strippers. In the known construction the further strippers are also juxtaposed in a continuous row over the length of their cutting roller. During normal forward operation of the cutting rollers the further strippers act in the main working direction as secondary strippers for stripping material which has not been stripped by the primary strippers. When reversing, i.e., for oppositely-directed operation of the cutting rollers, said secondary strippers act as primary strippers, while the primary strippers then act as secondary strippers. Thus, which strippers are primary and which are secondary is a function of the two possible rotation directions of the cutting roller.
Known stripping means have been found to consume up to 30% or more of the drive capacity available for moving the cutting rollers. Although a lower drive capacity might be sufficient for a given actual comminution process, a relatively higher drive capacity must be installed in order to ensure reliable operation. This increases the dimensions of the apparatus and increases costs, but still does not avoid the need for relatively frequent corrective operations, during which the cutting rollers are briefly driven in opposite directions for self-cleaning purposes. This maturally leads to a reduction in the working power of the shredding machine per unit of time.